Centrifuging wheel



y 1969 M. GEISSELER 3,444,651

CENTRIFUGING WHEEL Filed Nov. 30, 1966 Sheet of 5 y 0, 1969 M. GEISSELER3,444,651

CENTRIFUGING WHEEL Filed Nov. 30, 1966 Sheet 3 of 5 May 20, 1969 M.GEISSELER I CENTRIFUGING WHEEL 3 ors Sheet Filed Nov. 30, 1966 UnitedStates Patent 3,444,651 CENTRIFUGING WHEEL Max Geisseler, 14 Gemsgasse,8200 Schatfhausen, Switzerland Filed Nov. 30, 1966, Ser. No. 604,520Int. Cl. B24c 3/ 00, 3/02 U.S. Cl. 51-9 8 Claims ABSTRACT OF THEDISCLOSURE Centrifuging wheel comprising a preliminary accelerator,throwing blades which are symmetric with respect to a transverse axisabout which they may be turned about a 180 angle and reinstalled toutilize a different surface of the blades, anchoring means having wedgeshaped surfaces for retaining the blades while the wheel is rotating andapplies centrifugal force and holding means which apply elastic pressureto the blades and retain them when the wheel is at rest and permitremoval of the blades without releasing other fastening means.

The present invention concerns a centrifuging wheel having one or twowheel discs and interchangeable throwing blades for the acceleration ofmaterial to form jets, preferably of granular material, to a high speedfor the purpose of the surface treatment of workpieces, which forexample are to be cleaned or descaled. As is known the working principleof such a centrifuging wheel consists in that the jet medium is fed to awheel rotating rapidly and provided with radial throwing blades, as faras possible to the centre thereof, is accelerated outward in the radialdirection on the working surfaces of the throwing blades, and is thencapable due to centrifugal force of being thrown at a high speed fromthe circumference of the wheel against the workpiece to be handled.Embodiments are known in which the jet medium is fed from the face ofthe wheel by means of a fall pipe directly onto the inner part of thethrowing blades, and other embodiments in which a jet medium is fed intothe centre of the wheel and is accelerated therefrom by means ofcompressed air or in a mechanical manner outwardly in a radial directionand then passed to the throwing blades for further acceleration. It isknown from practical experience that the members feeding the jet mediumand the throwing blades, more particularly with centrifuging wheelshaving a high throughput and speed of throwing and more particularlywhen using hard metallic or mineral jet media, are subjected to highwear and tear due to the grinding action of the same, and consequentlyhave to be replaced from time to time.

The wear of the working surfaces of the throwing blades is in generalconsiderably stronger towards the circumference of the wheel, usuallydue to increasing speed of the jet medium than it is on the inlet sidefor the jet medium. As observation shows, particularly with centrifugingwheels of high output, the wear appears in the :form of local erosionsor grooves sometimes deep and generally in the shape of saw-teeth, whichhave steep flanks directed against the flow of the jet medium. The wearcomes about in that first of all individual small depressions form onthe smooth working surfaces of the new throwing blades, which more andmore take on the one-sided tooth shape. On the resulting steep flanksthe jet medium builds up with increasing erosion which for its partresults in a stronger digging out in front of the steep flanks. Theaforesaid fissuring of the working surfaces not only means that smoothsliding thereon of the jet medium is impossible and thereby thecentrifuged jet is torn apart in an undesirable manner, but also meansthat the throwing blades must be replaced when only a small part oftheir work material which is usually a high alloy and thereforeexpensive has fulfilled its purpose. By use of throwing blades, whichbecome thicker towards the circumference of the wheel, attempts havebeen made to increase their life. This however did not prevent thetearing apart of centrifugal jet after a certain wear, and as suchthrowing blades could only be built-in in a given position, the partwhich was less worn on the inlet side for the jet means was lost when achange became necessary.

Various constructional shapes of centrifuging wheels are known, which asfar as the fixing of the throwing blades is concerned differ only inthat with one type a single wheel disc is present having throwing bladesarranged on the face side, and in the other type two spaced wheel discsare provided with the throwing blades lying therebetween. In the firstmentioned embodiment the throwing blades are either secured onto theshaft of the wheels by means of a screw, or held in radial groovesusually of dovetail shape on the front side of the wheel discs by meansof securing elements. Amongst these there are also embodiments havingsymmetric throwing blades, which after a certain amount of wear can beturned through an angle of In known centrifuging wheels having two wheeldiscs the throwing blades are inserted with their longitudinal narrowedges into radial grooves arranged in the surfaces facing one another ofthe two discs, and are secured against a longitudinal displacementradially outward, caused by the centrifugal force, either by means ofadjustment screws, pivotable locking means, eccentrics, springs, orother moveable elements. With such centrifuging wheels the change ofblades is consequently always characterised by a relative movementbetween surfaces sliding on one another and the loosening andreinstalling of a separate securing element. In addition to this withthis type of fastening the throwing blades can only be built in a singleposition and the centrifuging wheels can only be built for use in asingle position and the centrifuging wheels can only be used for asingle direction of rotation. In addition with the known embodimentshaving positioning screws and eccentrics as the fixing elements it oftenhappens that the hardened throwing blades are subjected to an excessivelocal pressure whereby they become cracked and break prematurely. It isfurther known from working with the conventional centrifuging wheelsthat freely circulating jet medium, which so far could not be entirelystopped, damaged the exposed parts of the securing elements by degrees,and the fine particles of the jet medium and the dust which is alsopresent therein enters into all open cracks, and within a short timejams up either the throwing blades in their grooves, or the movablesecuring elements. Because of this, exchange of blades is often onlypossible with great effort and a corresponding exposure of time.Consequently the known centrifuging wheels have always had any onecombination from at least four of the faults set out below.

(1) The throwing blades are secured by any type of securing elementshaving surfaces which slide on one another; or

(2) Are inserted with their narrow longitudinal edges in radial groovesof the wheel discs; or

(3) Are secured against radial displacement toward the outside by meansof any type of securing elements having surfaces which slide upon oneanother; or

(4) Can only be built-in in a single position; or

(S) The centrifugal wheel can only be used in one direction of rotation.

The object of the invention is to eliminate at least the first four ofthe above summarised disadvantages and further aims at simplifying theconstruction and manufacture of both single and double disc centrifugingwheels, to raise the safety of operation by cutting out the heavyerosion and breakages of the throwing blades, to arrange for an easierand more rapid replacement of the same, to increase the life thereof bybetter utilisation of their material, and to maintain the desired shapeof the centrifuging jet with one and the same throwing blade for a longperiod of time. The centrifuging wheel according to the invention ischaracterised in that the wheel disc or discs or blade carriers and thethrowing blade have holding members mutually suitable anchors andanchorages receive the same, which are constructed symmetrically to atleast one cross-axis of the throwing blade and in such a way that thethrowing blades are held by the holding members in their workingposition, and on rotation of the centrifuging wheel retain themselves bythe centrifugal force working on them in such a way that an undesirabledisplacement relative to the body of the wheel is prevented; can beexchanged when the centrifugal wheel is at rest without the releasingand re-fixing of separate securing elements, and are capable of beingre-inserted when turned by an angle of 180 degrees about at least one oftheir cross axes.

The invention will be further apparent from the following descriptionwith reference to the several figures of the accompanying drawings,which show, by way of example only, a number of centrifuging wheelsembodying the invention.

Of the drawings:

FIG. 1 shows a cross section through a centrifuging wheel having twowheel discs and anchorages arranged on the longitudinal narrow side ofthe throwing blade, along the line C-C of FIG. 3.

FIG. 2 shows a cross section through a centrifuging wheel having onewheel disc and anchorages arranged on the longitudinal narrow side onthe throwing blade, along the line DD of FIG. 4.

FIG. 3 shows a cross section through a part of the centrifuging wheelalong the line AA of FIG. 1, one throwing blade being in view and oneomitted.

FIG. 4 shows a cross section through a part of a centrifuging wheelalong the line BB of FIG. 2, one throwing blade being in view and oneomitted.

FIG. 5 shows a cross section of an enlarged scale through a part of acentrifuging wheel along the line EE in FIG. 1.

FIG. 6 shows a cross section on an enlarged scale showing part of acentrifuging wheel along the line FF of FIG. 2.

FIG. 7 shows a cross section through the body of a wheel having twowheel discs and anchorages, on the rear side of the throwing blade,along the line II of FIG. 9.

FIG. 8 shows a cross section through the body of a Wheel, having onewheel disc and anchorages ranged on the rear side of the throwing blade,along the line II of FIG. 9.

FIG. 9 shows a cross section through a part of the body of the wheelalong the line 6-6 of FIG. 7 and HH of FIG. 8, one throwing blade beingin view and one along with the blade carrier being omitted.

FIG. 10 shows a cross section on an enlarged scale 4 through a part ofbody of the wheel along the line K-K of FIG. 7, and

FIG. 11 shows a cross section on an enlarged scale through a part of thebody of the wheel along the line L L of FIG. 8.

The Wheel hub 2 and the preliminary accelerator 3 are secured in amanner known per se on the end of a shaft 1 which is driven at highspeed by a power source which is not shown. The shell 4 for directingthe jet along with the partly shown feed pipe 5 are pivotally arrangedin a manner known per se in the sketched in centrifuging wheel housing6. The centrifuging wheel is secured on the wheel hub by means of ascrew 7. In FIGS. 1 and 7 the body of the wheel consists of the rearwheel discs 8 or 8' and the front wheel discs 9 or 9' which are, held ata given distance apart by means of spacing means such as bolts 10 or theblade support or carrier 11, and are rigidly connected together by meansof the screws 12 or 12'. In the centrifuging wheel shown in FIGS. 2 and8 the body of the wheel consists of only the rear wheel disc 13 or 13',the blade support or carrier 11 being secured to the latter wheel discby means of the screw 12'.

Two embodiments according to the invention are shown in FIGS. 1 to 6wherein throwing blades 14 or 15 radially arranged at an even distancefrom one another and conveniently of an even number, and held on alongitudinal narrow side 16 or 17 and anchored in the wheel discs, arelocated between the two wheel discs 8 and 9 or on the outer end face ofthe wheel disc 13. For this purpose the wheel discs are provied in thecross axis of the throwing blades 18 or 19 with support of holdingmembers 21 which conveniently have no surfaces sliding on one another,are for example firmly seated in a resilient shell 20 and by extendinginto the depressions 22 of the narrow sides of the throwing blades applypressure thereto. The throwing blades 14 and 15 have on theirlongitudinal narrow sides in addition to the transverse axes 18 or 19symmetrically arranged anchors 23 or 24 preferably having wedge-shapedengagement surfaces 25 or 26, which fit into the inner anchorages 27 or28 in the outer anchorages 29 or 30 of the wheel discs. The workingsurfaces 31 of the throwing blades are provided on all four longitudinalsides with borders 32 for the radial direction of the jet medium. Theshape of the throwing blade of the two disc centrifuging wheels issymmetrical both in regard to the radial longitudinal axis and also inregard to both transverse axes and with single disc centrifuging wheelsin relation to the cross axis 19.

Two embodiments according to the invention are shown in FIGS. 7 to 11wherein radially arranged throwing blades 14', which are held andanchored on their sides 33 in the blade supports or carriers 11 or 11'are located between the two wheel discs 8' and 9', or on the outer facesurface of the wheel disc 13'. For this purpose the blade supports orcarriers are fitted in the cross axes 34 of the throwing blades withholding members 21 which press into the depressions 22 in the rear sidesof the throwing blades. The throwing blades 14 have upon the rear sidein addition to the cross axis 34 symmetrically arranged anchors 35preferably having wedge-shaped engagement surfaces 36, which fit intothe anchorages 37 of the blade carrier, and for the radial guidance ofthe jet medium are provided on both longitudinal sides of their workingsurface 38 with borders 39. The anchors and anchorages preferably do notextend over the whole width of the blade, and are adapted to one anotherin such a way that thereby at the same time a lateral guide in theactual direction of the centrifuging wheel is obtained. The shape of thethrowing blades is both with two and single disc centrifugal wheelssymmetric to the cross axis 34.

As the following functional description will more clearly express, thereis obtained with the centrifuging wheels according to the invention,with simultaneously secure anchoring of the throwing blades, asimplification of the mounting and dismounting which was not previouslyknown as a considerable improvement in their life and thereby a higheroperational safety factor. In the embodiment shown by way of example inFIG. 1 the throwing blades are so inserted between the wheel discs formounting in radial direction to the axis of the centrifuging wheel andin a slightly inclined position on the radial axis that the anchor ofthe throwing blade first of all comes to rest in the inner anchorage ofthe wheel disc. The throwing blades are then pivoted into their radialaxes and drawn outwardly in the radial direction, so that the anchors ofthe throwing blades also engage into the outer anchorages. At the sametime the resilient holding members snap into the related depressions onthe narrow sides of the throwing blades and hold these in their workingposition. The dismounting of the throwing blades takes place in just assimple but however opposite manner. For this purpose by overcoming theholding power of the securing member they are pressed against the centreof the wheel out of the outermost anchorage, pivoted out on thecircumference of wheel, and then drawn out from the inner anchorage in aradial direction on the axis of the centrifuging wheel. In theembodiment shown in FIG. 2 the mounting of the throwing blades takesplace in that their anchors are inserted in the anchorages of the wheeldisc in the axial direction of the centrifuging wheel, the throw ingblades are then pressed against the holding member in the wheel disc andat the same time displaced towards the circumference of the wheel, untilthe holding members snap into the related depressions on thelongitudinal small sides of the throwing blades, which they then hold intheir working position. To dismount the throwing blades these, again byovercoming the tension of the holding member, are pressed towards thecentre of the wheel and after release of the anchors are removed in theaxial direction of the centrifuging wheel. The mounting and dismountingof the throwing blades in the embodiment shown in FIGS. 7 and 8 takesplace basically in exactly the same manner as has just been describedwith the exception that the throwing blades have to be moved in thetangential direction to the axis of the centrifuging wheel.

As soon as the centrifuging wheels according to the invention are setinto operation, they press themselves with great force against theirsupport surfaces due to the high centrifugal force acting upon them andthanks to the wedge-shaped engagement surfaces of their anchors. Incontrast to the known embodiments the centrifuging wheels according tothe invention do not have any securing elements with surfaces whichslide upon one another and also have no radial grooves for guiding thelongitudinal sides of the throwing blades, so that jamming of theseparts is quite out of the question. The embodiments according to theinvention as shown in FIGS. 2, 7 and 8 also have a further advantagethat both the holding member and also the anchor is completely coveredby the throwing blades, and consequently cannot be attacked and damagedby the jet medium whirling around on all sides. The wheel discs of theembodiments shown in FIGS. 7 and 8 further have the advantage that theyhave completely smooth face sides, which are simple to manufacture anddo not present any surfaces to be attacked by the whirling jet medium.If in centrifuging wheels in accordance with the invention, a usedthrowing blade is to be re-used in the embodiment shown in FIG. 1 it canat will either be built-in in such a way that the worn working surfacerests on the rear side, or so the more-used part on the circumference ofthe wheel rests on the inlet side for the jet medium which is subjectedto less stress. Whilst in the embodiment shown in FIG. 2 the wornworking surface of the throwing blade, on turning is necessarily alwayslocated on the rear side, in the embodiment shown in FIGS. 7 and 8 themore-used part of the working surface on the circumference of the wheelis always turned against the inlet side for the jet medium. With thecentrifuging wheels according to the invention it is consequentlypossible, either to locate a new working surface, or at least a lessworn part of the working surfaces on the throw-off side for the jetmedium which is subject to greater stresses, and in contrast to theknown embodiments thereby approximately double the life of the throwingblade without increasing the expense of the material, and also to retainthe centrifuging jet in the desired form with one and the same throwingblade for a much longer time.

The invention has been described with reference to the centrifugingwheels, in which the jet medium is fed to the centre of the wheel and ispre-accelerated by mechanical methods. Naturally the inventive thoughtscan be just as well used on other types of centrifuging wheels.Furthermore in the embodiments given by way of example only the holdingmembers and the anchorages are arranged on the body of the wheel and theanchors on the throwing blades. Embodiments are of course alsoconceivable where the retaining members and the anchorages are reversedwithout departing from the spirit of the invention. Furthermore in theembodiment shown by way of example only, centrifuging wheels are shownwhich have eight radially arranged throwing blades, whose workingsurfaces are even. According to the invention, embodiments are readilypossible which have a smaller or larger number of throwing blades. Dueto the lack of radial guide grooves on the longitudinal sides of thethrowing blades the invention also makes possible simpler solutions ofproblems in the construction and manufacturing techniques of thecentrifuging wheels, in which the throwing blades are inclinedbackwardly or forwardly as against the radial axes, or even have acurved workin g surface in the radial direction.

What I claim is:

1. A centrifuging wheel for accelerating material to high speedcomprising a central preliminary accelerator and at least one wheel diskdisposed circumferentially of said accelerator, a plurality of throwingblades disposed laterally of said at least one wheel disk, meansincluding resilient support members and depressions retaining saidblades on said at least one wheel disk and interengaging anchoring meanspresenting wedge shaped surfaces providing support for said throwingblades laterally of said at least one wheel disk in one operativeposition when centrifugal force acts on said blades, said throwingblades having a transverse axis and sides symmetrical to said transverseaxis about which axis said blades may be turned to another operativeposition, and said wedge shaped surfaces of said anchoring means beingadapted to provide support for said throwing blades in said otheroperative position when centrifugal force acts on said blades.

2. A centrifuging wheel in accordance with claim 1 where said resilientsupport members are located in said at least one disk and said bladespresent longitudinal sides and an anchor on at least one saidlongitudinal side adapted to engage said at least one disk.

3. A centrifuging wheel in accordance with claim 2 comprising a pair ofwheel disks, one on each side of said blades and anchoring means definedby resilient support members and de ressions intermediate each wheeldisk and the proximate sides of said blades.

4. A centrifuging wheel in accordance with claim 1 comprising a pair ofwheel disks, said anchoring means including blade supports extendingbetween said disks proximate said accelerator and said resilient supportmembers being provided intermediate said blade supports and the radiallyinward ends of said blades.

5. A centrifuging wheel in accordance with claim 1 where theconfiguration of said blades proximate said anchoring means provides aprotective cover for said anchoring means.

6. A centrifuging wheel according to claim 1 where 7 said anchoringmeans extend over part of the width of the throwing blades and are soadapted to one another that thereby a side guide in the axial directionof the centrifuging wheel is obtained.

7. A centrifuging wheel according to claim 1 Where the throwing bladeshave a radial axis and two transverse axes and a symmetrical form bothrelative to their radial axis and relative to their transverse axes.

8. A centrifuging wheel according to claim 1 Where the throwing bladeshave a symmetric shape in relation to their transverse axis.

8 References Cited UNITED STATES PATENTS 2,077,637 4/ 1937 Minich 5192,108,211 2/ 1938 Rosenberger et a1. 519 2,582,702 1/1952 Keefer 5193,242,615 3/1966 Physioc 519 FOREIGN PATENTS 696,005 8/1953 GreatBritain.

LESTER M. SWINGLE, Primary Examiner.

